The incident happened on the B1040 at Pondersbridge and forced the race to be temporarily halted.

The condition of the injured cyclist is not yet known.

Race organisers held talks whilst competitors waited to see if the race could re-start.

Following talks with team managers the race began again at 3pm’

Circuit of the Fens: race start Whittlesey

British Cycling’s live blog of the day reported: “To recap, after a serious accident in the support race forced a halt to the race, we are back under way on a shortened course.

“The riders will finish one last lap of the large loop, before heading back to Whittlesey and completing six laps of the small finishing circuit.”

“Both the support race and elite race will resume at 3pm. The support race will head to the finish at Whittlesey, while the elite riders will complete another lap of the large circuit before tackling six laps of the finishing circuit. Elite Road Series points will still be awarded.”

Huge crowds had lined the route earlier as the second annual Circuit of the Fens got under way.

A race in the British Cycling Grand Prix series, it is just one rung below the Tour of Britain it featurd up to 140 leading riders.

The 135-mile Circuit of the Fens started in Market Street.

A supporting race for amateur riders was also held over 84 miles, starting just after the main event.